Inbred corn line ZS1022

ABSTRACT

Broadly this invention provides inbred corn line ZS1022. The methods for producing a corn plant by crossing the inbred line ZS1022 are encompassed by the invention. Additionally, the invention relates to the various parts of inbred ZS1022 including culturable cells. This invention relates to hybrid corn seeds and plants produced by crossing the inbred line ZS1022 with at least one other corn line.

FIELD OF THE INVENTION

This invention is in the field of corn breeding, specifically relating to an inbred corn line designated ZS1022.

BACKGROUND OF THE INVENTION

The original maize plant was indigenous to the Western Hemisphere. The plants were weedlike and only through the efforts of early breeders was a cultivated crop species developed. The physical traits of maize are such that self pollination or cross pollination can occur. Each plant has a separate male and female flower, the tassel and ear, respectively. Natural pollination occurs when wind transfers pollen from tassel to the silks on the corn ears. This type of pollination contributed to the wide variation of maize varieties present in the Western Hemisphere.

The development of a planned breeding program for maize only occurred in the last century. Originally, maize was an open pollinated variety having heterogeneous genotypes. The maize farmer selected uniform ears from the yield of these genotypes and reserved them for planting the next season. The result was a field of maize plants that were segregating for a variety of traits. This type of maize selection lead to at most incremental increases in seed yield.

Large increases in seed yield were the result of the development of hybrid corn varieties in planned breeding programs. Hybrids were developed by selecting corn lines and selfing these lines for several generations to develop homozygous pure inbred lines and crossing selected inbred lines with other inbred lines to produce hybrid progeny (F1). Inbred lines can be difficult to produce since the inbreeding process in corn decreases the vigor. However, when two inbred lines are crossed, the hybrid plant evidences greatly increased vigor compared to open pollinated segregating maize plants. An important factor of the homozygosity and the homogeneity of the inbred lines is that the hybrid from any cross will always be the same, and can be reproduced.

The ultimate objective of the commercial maize seed companies is to produce high yielding, agronomically sound plants which perform well in certain regions or areas of the Corn Belt. To produce these types of hybrids, the companies must develop inbreds which carry needed traits into the hybrid combination. Hybrids are not uniformly adapted for the Corn Belt, but are specifically adapted for regions of the Corn Belt. Northern regions of the Corn Belt require shorter season hybrids than do southern regions of the Corn Belt. Hybrids that grow well in Colorado and Nebraska soils may not flourish in rich Illinois soil. Thus, a variety of major agronomic traits are important in hybrid combination for the various Corn Belt regions, and have an impact on hybrid performance.

Inbred line development and hybrid testing have been emphasized in the past half century in commercial maize production as a means to increase hybrid performance. Inbred development is usually done by pedigree selection. Pedigree selection can be selection in an F₂ population produced from a planned cross of two genotypes (often elite inbred lines), or selection of progeny of synthetic varieties, open pollinated, composite, or backcross populations. This type of selection is effective for highly inheritable traits, but other traits, for example, yield requires replicated test crosses at a variety of stages for accurate selection.

Maize breeders select for a variety of traits in inbreds that impact hybrid performance along with selecting for acceptable parental traits. Such traits include yield potential in hybrid combination; dry down; maturity; grain moisture at harvest; greensnap; resistance to root lodging; resistance to stalk lodging; grain quality; disease and insect resistance; ear and plant height; performance in different soil types such as: low level of organic matter, clay, sand, black, high pH, low pH; performance in: wet environments, drought environments, and no tillage conditions. These traits appear to be governed by a complex genetic system that makes selection and breeding of an inbred line extremely difficult. Even if an inbred in hybrid combination has excellent yield (a desired characteristic), it may not be useful because it fails to have acceptable parental traits such as deed yield, seed size, pollen production, good silks, plant height, etc.

To illustrate the difficulty of breeding and developing inbred lines, the following example is given. Two inbreds compared for similarity of 29 traits differed significantly for 18 traits between the two lines. If 18 simply inherited single gene traits were polymorphic with gene frequencies of 0.5 in the parental lines, and assuming independent segregation (as would essentially be the case if each trait resided on a different chromosome arm), then the specific combination of these traits as embodied in an inbred would only be expected to become fixed at a rate of one in 262,144 possible homozygous genetic combinations. Selection of the specific inbred combination is also influenced by the specific selection environment on many of these 18 traits which makes the probability of obtaining this one inbred even more remote. Thus, the general procedure of producing a non segregating F₁ generation and self pollinating to produce a F₂ generation that segregates for traits does not easily lead to a useful inbred. Great care and breeder expertise must be used in selection of breeding material to continue to increase yield and agronomics of inbreds and resultant commercial hybrids.

SUMMARY OF THE INVENTION

The present invention relates to an inbred corn line ZS1022. Specifically, this invention relates to plants and seeds of this line. Additionally, this relates to a method of producing hybrid seed corn from this inbred. More particularly, this invention relates to the unique combination of traits that combine in corn line ZS1022.

Generally then, broadly the present invention includes an inbred corn seed designated ZS1022. This seed produces a corn plant.

The invention also includes the tissue culture of regenerable cells of ZS1022 wherein the tissue regenerates plants having the genotype of ZS1022. The tissue culture is selected from the group consisting of leaves, pollen, embryos, roots, root tips, anthers, silk, flowers, kernels, ears, cobs, husks and stalks, and cells and protoplasts thereof. The corn plant regenerated from ZS1022 having ZS1022's genotype.

The invention extends to hybrid seed produced by planting, in pollinating proximity, seeds of corn inbred lines ZS1022 and another inbred line; cultivating corn plants resulting from said planting; preventing pollen production by the plants of one of the inbred lines; allowing natural cross pollinating to occur between said inbred lines; and harvesting seeds produced on plants of the inbred. The hybrid seed produced by hybrid combination of plants of inbred corn seed designated ZS1022 and plants of another inbred line. Hybrid plants grown from this hybrid seed.

The invention further includes a method of hybrid F1 production. A first generation (F1) hybrid corn plant produced by the process of planting, in pollinating proximity, seeds of corn inbred lines ZS1022 and another inbred line; cultivating corn plants resulting from said planting; preventing pollen production by the plants of one of the inbred lines; allowing natural cross pollinating to occur between said inbred lines; harvesting seeds produced on plants of the inbred; and growing a harvested seed.

A tissue culture of the regenerable cells of hybrid plants produced with use of ZS1022 genetic material. A tissue culture of the regenerable cells of the corn plant produced by the method described above.

DEFINITIONS

In the description and examples which follow, a number of terms are used. In order to provide a clear and consistent understanding of the specifications and claims, including the scope to be given such terms, the following definitions are provided.

BL MOIST

The moisture percentage of the grain at black layer, ie, when 50% of the plants per plot have reached physiological maturity.

COLD GERM

Cold Germ is a measurement of seed germination under cold soil conditions. Data is reported as percent of seed germinating.

ECB

European corn borer a maize eating insect. ECBI is the first brood generation of European corn borers. ECBII is the second generation of European corn borers.

EMERGE

The number of emerged plants per plot (planted at the same seedling rate) collected when plants have two fully developed leaves.

GI

This is a selection index which provides a single quantitative measure of the worth of a hybrid based on four traits. Yield is the primary trait contributing to index values. The GI value is calculated by combining stalk lodging, root lodging, yield and dropped ears according to the attached mathematical formula:

    GI=100+0.5 (YLD)-0.9 (% STALK LODGE)-0.9 (% ROOT LODGE)-2.7 (% DROPPED EAR)

GLS

Grey Leaf Spot (Cercospora Zeae) disease rating. This is rated on a 1-9 scale with a "1" being very susceptible, and a "9" being very resistant.*

GW

Goss' Wilt (Corynebacterium nebraskense). This is rated on a 1-9 scale with a "1" being very susceptible, and a "9" being very resistant.*

HEATP10

The number of Growing Degree Units (GDU's) or heat units required for an inbred line or hybrid to have approximately 10 percent of the plants shedding pollen. This trait is measured from the time of planting. Growing Degree Units are calculated by the Barger Method where the GDU's for a 24 hour period are: ##EQU1## The highest maximum temperature used is 86° F. and the lowest minimum temperature used is 50° F. For each inbred or hybrid it takes a certain number of GDU's to reach various stages of plant development.

HEATBL

The number of GDU's after planting when approximately 50 percent of the inbred or hybrid plants in a plot have grain which has reached physiological maturity (black layer).

HEATPEEK

The number of GDU's after planting of an inbred when approximately 50 percent of the plants show visible tassel extension.

HEATP50

The number of GDU's required for an inbred or hybrid to have approximately 50 percent of the plants shedding pollen. Growing Degree Units are calculated by the Barger Method as shown in the HEATP10 definition.

HEATP90

The number of GDU's accumulated from planting when the last 100 percent of plants in an inbred or hybrid are still shedding enough viable pollen for pollination to occur. Growing Degree Units are calculated by the Barger Method as shown in the HEATP10 definition.

HEATS10

The number of GDU's required for an inbred or hybrid to have approximately 10 percent of the plants with silk emergence of at least 0.5 inches. Growing Degree Units are calculated by the Barger Method as shown in the HEATP10 definition.

HEATS50

The number of GDU's required for an inbred or hybrid to have approximately 50 percent of the plants with silk emergence of at least 0.5 inches. Growing Degree Units are calculated by the Barger Method as shown in the HEATP10 definition.

HEATS90

The number of GDU's required for an inbred or hybrid to have approximately 90 percent of the plants with silk emergence of at least 0.5 inches. Growing Degree Units are calculated by the Barger Method as shown in the HEATP10 definition.

MDMV_(A)

Maize Dwarf Mosaic Virus strain A. The cord is rated on a 1-9 scale with a "1" being very susceptible, and a "9" being very resistant. *

MDMV_(B)

Maize Dwarf Mosaic Virus strain B. This is rated on a 1-9 scale with a "1" being very susceptible and a "9" being very resistant.*

MOISTURE

The average percentage grain moisture of an inbred or hybrid at harvest time.

NLB

Northern Leaf Blight (Exserohilum turcicum) disease rating. This is rated on a 1-9 scale with a "1" being very susceptible, and a "9" being very resistant.*

PCT TILLER

The total number of tillers per plot divided by the total number of plants per plot.

PLANT

This term includes plant cells, plant protoplasts, plant cell tissue cultures from which corn plants can be regenerated, plant calli, plant clumps, and plant cells that are intact in plants or parts of plants, such as embryos, pollen, flowers, kernels, ears, cobs, leaves, husks, stalks, roots, root tips, anthers, silk and the like.

PLANT HEIGHT

The distance in centimeters from ground level to the base of the tassel peduncle.

RM

Predicted relative maturity based on the moisture percentage of the grain at harvest. This rating is based on known set of checks and utilizes standard linear regression analyses and is referred to as the Minnesota Relative Maturity Rating System.

SHED

The volume of pollen shed by the male flower rated on a 1-9 scale where a "1" is a very light pollen shedder, a "4.5" is a moderate shedder, and a "9" is a very heavy shedder. The Table(s) 3 have reduced the 1-9 shed scale to a 1-3 shed scale. Any shed on Table 3 can be multiplied by 3 to reach the 1-9 shed scale.

SLB

Southern Leaf Blight (Bipolaris maydis) disease rating. This is rated on a 1-9 scale with a "1" being very susceptible, and a "9" being very resistant.*

TWT

The measure of the weight of grain in pounds for a one bushel volume adjusted for percent grain moisture.

VIGOR

Visual rating of 1 to 9 made 2-3 weeks post-emergence where a "1" indicates very poor early plant development, and a "9" indicates superior plant development.

WARM GERM

A measurement of seed germination under ideal (warm, moist) conditions. Data is reported as percent of seeds germinating.

YIELD (YLD)

Actual yield of grain at harvest adjusted to 15.5% moisture. Measurements are reported in bushels per acre.

% DROPPED EARS (DE)

The number of plants per plot which dropped their primary ear divided by the total number of plants per plot.

% LRG FLAT

Percentage by weight of shelled corn that passes through a 26/64 inch round screen and a 14/64 inch slot screen, but does not pass through a screen with 20.5/64 inch round openings.

% LRG ROUND

Percentage by weight of shelled corn that passes through a 26/64 inch round screen, but does not pass through a 14/64 inch slot screen or a screen with 20.5/64 inch round openings.

% MED FLAT

Percentage by weight of shelled corn that passes through a 20.5/64 inch round screen and a 13/64 inch slotted screen, but does not pass through a screen with 17/64 inch round openings.

% MED ROUND

Percentage by weight of shelled corn that passes through a 20.5/64 inch round screen, but does not pass through a 13/64 inch slot screen or a screen with 17/64 inch round openings.

% SML FLAT

Percentage by weight of shelled corn that passes through a 17/64 inch round screen and a 12/64 inch slotted screen, but does not pass through a screen with 15/64 inch round openings.

% SML ROUND

Percentage by weight of shelled corn that passes through a 17/64 inch round screen, but does not pass through a 12/64 inch slotted screen or a screen with 15/64 inch round openings.

% ROOT LODGE (RL)

Percentage of plants per plot leaning more that 30 degrees from vertical divided by total plants per plot.

% STALK LODGE (SL)

Percentage of plants per plot with the stalk Broken below the primary ear node divided by the total plants per plot. * Resistant--on a scale of 1-9 with 9 evidencing the trait most strongly: 1-2.9 ratings are susceptible, 3-5.9 ratings are intermediate, and 6-9 ratings are resistant.

DETAILED DESCRIPTION OF THE INVENTION

ZS1022 can be used as a female or a male line due to its pollen shed and seed production abilities. This ZS1022 line evidences good to excellent late season stay green and plant integrity. Additionally, ZS1022 has good general combining ability and specific combining ability with above average root lodging resistance.

This inbred is a prolific plant. ZS1022 produces 2 ears and has low number of barren plants. This inbred is a medium to medium tall line. This inbred produces hybrids which are tall and robust with good ear placement. This inbred is rated 5.8 for ECBII. The inbred appears to carry this second generation resistance into its hybrids. In a specific hybrid combination ZS1022 was combined with a second inbred having an ECBII rating of 4.3. The resultant hybrid consistently is rated at 6.1 for ECBII tolerance.

ZS1022 was developed from a cross of inbred LH93 with inbred LH123. ZS1022 makes earlier hybrids than does LH123 and has better traits for production as a female inbred. ZS1022 is shorter, but more prolific than LH123.

The inbred has shown uniformity and stability within the limits of environmental influence for all the traits as described in the Variety Description Information (Table 1) that follows. Most of the data in the Variety Description information was collected at Slater, Iowa.

The inbred has been self-pollinated for a sufficient number of generations to give inbred uniformity. During plant selection in each generation, the uniformity of plant type was selected to ensure homozygosity and phenotypic stability. The line has been increased in isolated farmland environments with data on uniformity and agronomic traits being observed to assure uniformity and stability. No variant traits have been observed or are expected in ZS1022.

The best method of producing the invention, ZS1022 which is substantially homozygous, is by planting the seed of ZS1022 which is substantially homozygous and self-pollinating or sib pollinating the resultant plant in an isolated environment, and harvesting the resultant seed or the resultant pollen. The best method of making ZS1022 hybrids is to use the male portion (the pollen) or the female portion in the development of hybrid seed, or regenerate said hybrid from culture tissue having regenerable cells.

                                      TABLE 1                                      __________________________________________________________________________     ZS1022                                                                         VARIETY DESCRIPTION INFORMATION                                                #1 Type: Dent                                                                  #2 Region Best Adapted: Central and Eastern Corn Belt                          __________________________________________________________________________     #3   MATURITY                                                                  DAYS HEATUNITS                                                                 80   1514       FROM PLANTING TO 50% OF PLANTS IN SILK                         80   1514       FROM PLANTING TO 50% OF PLANTS IN POLLEN                       7               FROM 10% TO 90% POLLEN SHED                                    __________________________________________________________________________     #4   PLANT                                                                     DATA                                                                           2               ANTHOCYANIN OF BRACE ROOTS: 1=ABSENT 2=FAINT 3=MODERATE                        4=DARK                                                         __________________________________________________________________________     #5   LEAF                                                                      COLOR                                                                               /DATA                                                                     3/   DARK GREEN LEAF COLOR **MUNSELL CODE-7.5GY 3/2                            4               LEAF SHEATH PUBESCENCE (1=NONE TO (=PEACH FUZZ)                5               MARGINAL WAVES (1=NONE TO 9=MANY)                              6               LONGITUDINAL CREASES (1=NONE TO 9=MANY)                        __________________________________________________________________________     #6   TASSEL                                                                    COLOR                                                                               /DATA                                                                     6               POLLEN SHED (0=STERILE TO 9=HEAVY SHEDDER)                     1    /LIGHT GREEN                                                                              ANTHER COLOR **MUNSELL CODE-2.5 GY 8/6                         2               GLUME COLOR **MUNSELL CODE-5GY 6/6                             2               BAR GLUME: 1=ABSENT 2=PRESENT                                  __________________________________________________________________________     #7A  EAR (UNHUSKED DATA)                                                       COLOR                                                                               /DATA                                                                     5    /GREEN-YELLOW                                                                             SILK COLOR (3 DAYS AFTER EMERGE) **MUNSELL CODE-2.5GY                          8/10                                                           2    /MEDIUM GREEN                                                                             FRESH HUSK (25 DAYS AFTER 50% SILK) **MUNSELL CODE-5GY                         6/8                                                            22   /TAN       DRY HUSK COLOR (65 DAYS AFTER 50% SILK **MUNSELL                               CODE-2.5Y 8/4                                                  1               POSITION OF EAR AT DRY HUSK: 1=UPRIGHT 2=HORIZONTAL                            3=PENDENT                                                      4    HUSK TIGHTNESS (1=VERY LOOSE TO 9=VERY TIGHT)                             2    HUSK EXTENSION AT HARVEST: 1=EXPOSED EAR 2=8CM 3=8-10CM                   __________________________________________________________________________          4=>10CM                                                                   #7B  EAR (HUSKED DATA)                                                         DATA                                                                           2    KERNEL ROWS: 1=INDINSTINCT 2=DISTINCT                                     1    ROW ALIGNMENT: 1=STRAIT 2=SLIGHT CURVE 3=SPIRAL                           2    EAR TAPPER: 1=STRAIT 2=AVERAGE 3=EXTREME                                  __________________________________________________________________________     #8   KERNEL (DRY)                                                              COLOR                                                                               /DATA                                                                     1               ALEURONE COLOR PATTERN: 1=HOMO 2=SEG                           8    /YELLOW-ORANGE                                                                            ALEURONE COLOR **MUNSELL CODE-5Y 8/12                          8    /YELLOW-ORANGE                                                                            HARD ENDOSPERM COLOR **MUNSELL CODE-7.5YR 7/10                 3               ENDOSPERM TYPE                                                 7    /YELLOW    CROWN COLOR **MUNSELL CODE-2.5Y 8/10                           __________________________________________________________________________     #9   COB                                                                       COLOR                                                                          23   /BROWN     COB COLOR **MUNSELL CODE-10R 4/6                               __________________________________________________________________________     COLOR CHOICES (Use in conjunction with Munsell color code to describe all      color choices                                                                  01 = Light Green                                                                           06 = Pale Yellow                                                                         11 = Pink 16 = Pale Purple                                                                         21 = Buff                            02 = Medium Green                                                                          07 = Yellow                                                                              12 = Light Red                                                                           17 = Purple                                                                              22 = Tan                             03 = Dark Green                                                                            08 = Yellow-Orange                                                                       13 = Cherry Red                                                                          18 = Colorless                                                                           23 = Brown                           04 = Very Dark Green                                                                       09 = Salmon                                                                              14 = Red  19 = White                                                                               24 = Bronze                          05 = Green-Yellow                                                                          10 = Pink-Orange                                                                         15 = Red & White                                                                         20 = White Capped                                                                        25 = Variegated (Describe)                                                     26 = Other (Describe)                __________________________________________________________________________                                N MEAN STD. T-STAT                                                                             PROB   95% CI                       __________________________________________________________________________     EAR HEIGHT(CM)             15                                                                               84.73                                                                                7.83                                                                               41.90                                                                              0.0000 (80.77, 88.70)               LENGTH OF PRIMARY EAR LEAF(CM)                                                                            15                                                                               99.60                                                                                2.61                                                                               143.2                                                                              0.0000 (95.28, 97.92)               WIDTH OF PRIMARY EAR LEAF(CM)                                                                             15                                                                               7.40  0.34                                                                               84.78                                                                              0.0000 (7.23, 7.57)                 TOP EAR INTERNODE(CM)      15                                                                               15.77                                                                                1.18                                                                               51.83                                                                              0.0000 (15.17, 16.36)               DEGREE OF LEAF ANGLE       15                                                                               27.40                                                                                2.32                                                                               45.67                                                                              0.0000 (26.22, 28.58)               # OF EARS PER PLANT        15                                                                               1.93  0.26                                                                               29.00                                                                              0.0000 (1.80, 2.06)                 # OF LEAVES ABOVE TOP EAR  15                                                                               4.87  0.35                                                                               53.57                                                                              0.0000 (4.69, 5.04)                 # OF PRIMARY LATERAL TASSEL BRANCHES                                                                      15                                                                               5.93  0.80                                                                               28.77                                                                              0.0000 (5.53, 6.34)                 PLANT HEIGHT (CM)          15                                                                               166.4                                                                                7.00                                                                               92.09                                                                              0.0000 (162.9, 169.9)               TASSEL LENGTH (CM)         15                                                                               47.27                                                                                1.91                                                                               95.98                                                                              0.0000 (46.30, 48.23)               TASSEL BRANCHING ANGLE     15                                                                               31.80                                                                                5.28                                                                               23.32                                                                              0.0000 (29.13, 34.47)               # OF TILLER PER PLANTS     15                                                                               0.00  0.00           (0.00, 0.00)                 WEIGHT PER 100 KERNELS (GM)                                                                               15                                                                               27.12                                                                                4.45                                                                               23.61                                                                              0.0000 (24.87, 29.37)               EAR LENGTH (CM)            15                                                                               16.47                                                                                0.84                                                                               75.71                                                                              0.0000 (16.04, 16.89)               EAR WEIGHT (GM)            15                                                                               102.6                                                                               14.98                                                                               26.52                                                                              0.0000 (95.00, 110.2)               # OF KERNEL ROWS           15                                                                               10.27                                                                                1.49                                                                               26.75                                                                              0.0000 (9.51, 11.02)                COB DIAMETER AT MID-POINT (MM)                                                                            15                                                                               21.21                                                                                1.01                                                                               81.13                                                                              0.0000 (20.70, 21.73)               EAR DIAMETER AT MID-POINT (MM)                                                                            15                                                                               35.92                                                                                1.17                                                                               119.4                                                                              0.0000 (35.33, 36.51)               KERNEL LENGTH (MM)         15                                                                               10.65                                                                                0.72                                                                               56.92                                                                              0.0000 (10.29, 11.02)               KERNEL THICKNESS (MM)      15                                                                               4.42  0.35                                                                               48.78                                                                              0.0000 (4.24, 4.60)                 KERNEL WIDTH (MM)          15                                                                               8.73  0.69                                                                               49.26                                                                              0.0000 (8.38, 9.07)                 % ROUND KERNELS (SHAPE GRADE)                                                                             15                                                                               30.13                                                                               10.96                                                                               10.65                                                                              0.0000 (24.59, 35.68)               SHANK LENGTH               15                                                                               9.27  2.21                                                                               16.25                                                                              0.0000 (8.15, 10.39)                #11 DISEASE RESISTANCE-                                                                        Common corn rust = 4.8                                                         Northern leaf blight = 2                                                       Gray leaf spot = 2                                                             Maize dwarf mosaic virus strain B = 1                          #12 Inbreds most useful for comparison are its parents LH93                    and LH123. The best comparable inbreds based on genetic                        makeup and combining ability/maturity are LH94A and LH51.                      __________________________________________________________________________

The Munsell code is a reference book of color which is known and used in the industry and by persons with ordinary skill in the art of plant breeding.

The purity and homozygosity of inbred ZS1022 is constantly being tracked using isozyme genotypes as shown in Table 2.

Izsozyme Genotypes for ZS1022

Isozyme data were generated for inbred corn line ZS1022 according to procedures known and published in the art. The data in Table 2 gives the electrophoresis data on ZS1022.

                                      TABLE 2                                      __________________________________________________________________________     ELECTROPHORESIS RESULTS FOR ZS1022                                             INBRED                                                                               ACP1                                                                               ACP4                                                                               ADH MDH1                                                                               MDH2                                                                               PGD1                                                                               PGD2                                                                               PH1                                                                               PGM IDH2                                  __________________________________________________________________________     ZS1022                                                                               11  22  22  22  11  11  11  22 22  22                                    __________________________________________________________________________

Inbred and Hybrid Performance of ZS1022

The traits and characteristics of inbred corn line ZS1022 are listed and compared with other inbreds and/or compared with inbreds in hybrid combination. This data evidences many important characteristics and traits of ZS1022.

The inbred comparison data in Table 3A has limited experiments, but it compares ZS1022 with its parent LH123. ZS1022 is higher yielding with lower grain harvest moisture than LH123. ZS1022 has a lower vigor score with a higher emergence rating than its parent LH123. ZS1022 flowers (HEATP10-HEATP90 and HEATS50-HEATS90) significantly earlier than LH123. ZS1022 reaches that Heat Peek significantly earlier than LH123. ZS1022 is shorter statured, but has higher ear placement than LH123. LH123 has an ECBI and ECBII rating of 4.2 and 6.2, respectively over seven years. ZS1022 has ECBI and ECBII rating of 5.2 and 5.8, respectively over two years.

                                      TABLE 3A                                     __________________________________________________________________________     PAIRED INBRED COMPARISON DATA                                                                          PCT  PLANT EAR       EAR   PCT                         YEAR   INBRED                                                                               VIGOR                                                                               EMERGE                                                                               TILLER                                                                              HEIGHT                                                                               HEIGHT                                                                               SHED                                                                               QUALITY                                                                              BARREN                      __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               5.3  86.9       175.3 88.9  1.5 2.0                                      LH123 7.0  79.4       190.5 81.9  2.3 2.0                                      # EXPTS                                                                              2    2          2     2     1   2                                        DIFF  1.8  7.5        15.2  7.0   0.0 0.0                                      PROB  0.090***                                                                            0.742      0.374 0.597                                       __________________________________________________________________________     YEAR   INBRED                                                                               HEATP10                                                                             HEATP50                                                                              HEATP90                                                                              HEATS10                                                                              HEATS50                                                                              HEATS90                              __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               1429 1480  1532  1431  1468  1525                                        LH123 1499 1557  1598  1553  1596  1634                                        # EXPTS                                                                              2    2     2     2     2     2                                           DIFF  70   78    65    122   128   108                                         PROB  0.046**                                                                             0.072***                                                                             0.005*                                                                               0.126 0.007*                                                                               0.084***                             __________________________________________________________________________                               BL   ROOT  % STALK                                                                              % DROPPED                                                                              MOISTURE                    YEAR   INBRED                                                                               HEATPEEK                                                                              HEATBL                                                                               MOIST                                                                               LODGE LODGE EARS    MOISTURE                                                                              YIELD                __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               1375   2548  31.0                     10.0   68.0                        LH123 1426   2654  36.0                     10.6   30.0                        # EXPTS                                                                              2      1     1                        2      2                           DIFF  51     10.6  5.0                      0.5    38.0                        PROB  0.002*                                0.806                       __________________________________________________________________________                  WARM COLD % LRG                                                                               % LRG                                                                               % MED                                                                               % MED                                                                               % SML                                                                               % SML                          YEAR   INBRED                                                                               GERM GERM ROUND                                                                               FLAT ROUND                                                                               FLAT ROUND                                                                               FLAT                           __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               98.0 95.0 22.4 35.5 18.1 21.3 1.0  0.8                                   LH123 93.0 88.8 16.9 21.8 36.7 21.5 1.7  0.9                                   # EXPTS                                                                              1    1    2    2    2    2    2    2                                     DIFF  3.0  2.5  5.5  13.7 18.6 0.3  0.7  0.1                                   PROB            0.742                                                                               0.307                                                                               0.010**                                       __________________________________________________________________________

Table 3B compares ZS1022 to LH93, its other parent. ZS1022 has better ratings on both seedling vigor and a higher early stand count (emerge). ZS1022 has a higher yield and slightly higher moisture than LH93. ZS1022 is a taller inbred with higher ear placement. LH93 has an ECBI rating of 5.8 over seven years of testing and ZS1022 has 5.2 over two years of testing; ZS1022 has an ECBII rating of 5.8 over two years of testing and LH93 has a 6.9 rating over seven years.

                                      TABLE 3B                                     __________________________________________________________________________     PAIRED INBRED COMPARISON DATA                                                                          PCT  PLANT EAR       EAR   PCT                         YEAR   INBRED                                                                               VIGOR                                                                               EMERGE                                                                               TILLER                                                                              HEIGHT                                                                               HEIGHT                                                                               SHED                                                                               QUALITY                                                                              BARREN                      __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               6.0  88.7       180.3 91.4  1.5 2.3                                      LH93  3.7  74.1       159.2 75.8  1.5 3.0                                      # EXPTS                                                                              3    3          3     3     1   3                                        DIFF  2.3  14.6       21.2  15.7  0.5 0.7                                      PROB  0.118                                                                               0.118      0.035**                                                                              0.014**   0.184                             __________________________________________________________________________     YEAR   INBRED                                                                               HEATP10                                                                             HEATP50                                                                              HEATP90                                                                              HEATS10                                                                              HEATS50                                                                              HEATS90                              __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               1353 1393  1431  1362  1395  1444                                        LH93  1360 1397  1436  1422  1458  1487                                        # EXPTS                                                                              3    3     3     3     3     3                                           DIFF  7    4     4     60    64    43                                          PROB  0.543                                                                               0.670 0.810 0.237 0.215 0.225                                __________________________________________________________________________                               BL   ROOT  % STALK                                                                              % DROPPED                                                                              MOISTURE                    YEAR   INBRED                                                                               HEATPEEK                                                                              HEATBL                                                                               MOIST                                                                               LODGE LODGE EARS    MOISTURE                                                                              YIELD                __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               1303   2548  31.0                     9.2    64.2                        LH93  1309   2437  30.0                     8.9    41.1                        # EXPTS                                                                              3      1     1                        3      3                           DIFF  6      111   1.0                      0.3    23.0                        PROB  0.349                                 0.708                       __________________________________________________________________________                  WARM COLD % LRG                                                                               % LRG                                                                               % MED                                                                               % MED                                                                               % SML                                                                               % SML                          YEAR   INBRED                                                                               GERM GERM ROUND                                                                               FLAT ROUND                                                                               FLAT ROUND                                                                               FLAT                           __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               96.5 93.8 15.7 24.0 25.0 21.2 8.2  3.5                                   LH93  96.3 93.0 1.3  2.1  27.9 29.9 16.1 16.2                                  # EXPTS                                                                              1    1    3    3    3    3    3    3                                     DIFF  1.5  1.0  14.4 21.8 2.9  8.8  7.9  12.7                                  PROB            0.296                                                                               0.216                                                                               0.840                                         __________________________________________________________________________

Table 3C shows a comparison of ZS1022 and LH51 in which ZS1022 is higher yielding with lower grain harvest moisture. ZS1022 flowers significantly earlier than LH51 (HEATP10-90 and HEATS10-90). ZS1022 has better warm and cold germination than LH51.

                                      TABLE 3C                                     __________________________________________________________________________     PAIRED INBRED COMPARISON DATA                                                                          PCT  PLANT EAR       EAR   PCT                         YEAR   INBRED                                                                               VIGOR                                                                               EMERGE                                                                               TILLER                                                                              HEIGHT                                                                               HEIGHT                                                                               SHED                                                                               QUALITY                                                                              BARREN                      __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               5.3  86.9       175.3 88.9  1.5 2.0                                      LH51  5.0  81.4       156.2 78.4  2.0 2.5                                      # EXPTS                                                                              4    4          4     4     2   4                                        DIFF  0.3  5.6        19.0  10.5  0.5 0.5                                      PROB  0.182                                                                               0.475      0.005*                                                                               0.029**   0.182                             __________________________________________________________________________     YEAR   INBRED                                                                               HEATP10                                                                             HEATP50                                                                              HEATP90                                                                              HEATS10                                                                              HEATS50                                                                              HEATS90                              __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               1429 1480  1532  1431  1468  1525                                        LH51  1479 1524  1566  1521  1559  1608                                        # EXPTS                                                                              4    4     4     4     4     4                                           DIFF  50   45    33    90    91    82                                          PROB  0.034**                                                                             0.037**                                                                              0.034**                                                                              0.026**                                                                              0.008*                                                                               0.003*                               __________________________________________________________________________                               BL   ROOT  % STALK                                                                              % DROPPED                                                                              MOISTURE                    YEAR   INBRED                                                                               HEATPEEK                                                                              HEATBL                                                                               MOIST                                                                               LODGE LODGE EARS    MOISTURE                                                                              YIELD                __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               1375   2548  31.0                     10.0   68.0                        LH51  1408   2605  30.5                     10.3   52.2                        # EXPTS                                                                              4      1     1                        4      4                           DIFF  33     58    0.5                      0.3    15.7                        PROB  0.102                                 0.638                       __________________________________________________________________________                  WARM COLD % LRG                                                                               % LRG                                                                               % MED                                                                               % MED                                                                               % SML                                                                               % SML                          YEAR   INBRED                                                                               GERM GERM ROUND                                                                               FLAT ROUND                                                                               FLAT ROUND                                                                               FLAT                           __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               98.0 95.0 22.4 35.5 18.1 21.3 1.0  0.8                                   LH51  96.0 77.9 29.8 41.0 20.9 6.8  0.9  0.3                                   # EXPTS                                                                              2    2    4    4    4    4    4    4                                     DIFF  3.0  12.5 7.4  5.6  2.8  14.6 0.2  0.5                                   PROB            0.457                                                                               0.007*                                                                              0.041**                                       __________________________________________________________________________

The results in Table 3D show ZS1022 has higher yield and higher grain harvest moisture than LH94A. ZS1022 is a taller inbred with a significantly higher ear placement than LH94A. ZS1022 has a better seedling vigor rating and a significantly higher early stand count than does LH94A.

                                      TABLE 3D                                     __________________________________________________________________________     PAIRED INBRED COMPARISON DATA                                                                          PCT  PLANT EAR       EAR   PCT                         YEAR   INBRED                                                                               VIGOR                                                                               EMERGE                                                                               TILLER                                                                              HEIGHT                                                                               HEIGHT                                                                               SHED                                                                               QUALITY                                                                              BARREN                      __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               5.3  86.9       175.3 88.9  1.5 2.0                                      LH94A 3.8  64.4       156.2 81.9  2.3 2.3                                      # EXPTS                                                                              2    2          2     2     1   2                                        DIFF  1.5  22.5       19.0  7.0   0.0 0.3                                      PROB       0.070***   0.166 0.058***  0.500                             __________________________________________________________________________     YEAR   INBRED                                                                               HEATP10                                                                             HEATP50                                                                              HEATP90                                                                              HEATS10                                                                              HEATS50                                                                              HEATS90                              __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               1429 1480  1532  1431  1468  1525                                        LH94A 1437 1478  1526  1484  1530  1567                                        # EXPTS                                                                              2    2     2     2     2     2                                           DIFF  7    1     6     53    62    42                                          PROB  0.489                                                                               0.939 0.811 0.423 0.376 0.333                                __________________________________________________________________________                               BL   ROOT  % STALK                                                                              % DROPPED                                                                              MOISTURE                    YEAR   INBRED                                                                               HEATPEEK                                                                              HEATBL                                                                               MOIST                                                                               LODGE LODGE EARS    MOISTURE                                                                              YIELD                __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               1375   2548  31.0                     10.0   68.0                        LH94A 1375   2374  30.5                     9.1    44.8                        # EXPTS                                                                              2      1     1                        2      2                           DIFF  0      174   0.5                      0.9    23.2                        PROB  1.000                                 0.151                       __________________________________________________________________________                  WARM COLD % LRG                                                                               % LRG                                                                               % MED                                                                               % MED                                                                               % SML                                                                               % SML                          YEAR   INBRED                                                                               GERM GERM ROUND                                                                               FLAT ROUND                                                                               FLAT ROUND                                                                               FLAT                           __________________________________________________________________________     OVERALL                                                                               ZS1022                                                                               98.0 95.0 22.4 35.5 18.1 21.3 1.0  0.8                                   LH94A 97.5 96.5 2.9  3.6  24.5 30.2 12.7 18.5                                  # EXPTS         2    2    2    2    2    2                                     DIFF            19.5 31.9 6.5  8.9  11.6 17.8                                  PROB            0.381                                                                               0.199                                                                               0.634                                         __________________________________________________________________________

Table 4 shows the GCA (general combining ability) estimates of ZS1022 compared with the GCA estimates of its two parents, LH123 and LH93. The estimates show the general combining ability is weighted by the number of experiment/location combinations in which the specific hybrid combination occurs. The interpretation of the data for all traits is that a positive comparison is a practical advantage. A negative comparison is a practical disadvantage. The general combining ability of an inbred is clearly evidenced by the results of the general combining ability estimates. This data compares the inbred parent in a number of hybrid combinations to a group of "checks". The check data is from other companies' hybrids, particularly the leader in the industry and ICI Seeds' commercial products and pre-commercial hybrids which were grown in the same sets and locations.

LH123 was placed in 62 different hybrid combinations with a total of 376 experiments. LH93 was placed in 10 different hybrid combinations with a total of 801 experiments. ZS1022 was placed in 187 hybrid combinations with a total of 1921 experiments.

                                      TABLE 4                                      __________________________________________________________________________     N      GI YM YLD MOIST                                                                               SL RL DE TWT RM                                          __________________________________________________________________________     ZS1022                                                                             1921                                                                              1.0                                                                               -0.3                                                                              0.8 -1.1 -0.3                                                                               0.9                                                                              0.0                                                                               -0.7                                                                               119                                         LH93                                                                                801                                                                              -4.5                                                                               0.1                                                                              -10.1                                                                               1.6 -0.9                                                                               1.5                                                                              0.0                                                                               -1.7                                                                               113                                         LH123                                                                               376                                                                              -2.1                                                                              -0.6                                                                              -3.4                                                                               -1.6  0.2                                                                              -0.6                                                                              0.0                                                                                0.0                                                                               123                                         __________________________________________________________________________

ZS1022 in hybrid combination has a better GI rating at 1.0 than either parent. LH93 has a -4.5 and LH123 has a -2.1. In yield by moisture ZS1022 in hybrid combination has a higher rating than LH123 ratings and a lower rating than its other parent LH93. The comparison shows ZS1022 in hybrid combination has markedly higher yield ratings than both parents. ZS1022 having 0.8, LH123 having -3.4, and LH93 having -10.1. ZS1022 rates a higher score for grain harvest moisture than LH123 at -1.6 and a lower score than LH93. In stalk lodging, ZS1022's score in hybrid combination was better than LH93 and less than LH123. ZS1022's root lodging score was better than LH123 and less than LH93. The drop ear rating of the three inbreds was the same. ZS1022 scored higher in test weight than LH93 but less than LH123.

In all listed ratings, ZS1022 has a better rating than at least one of its parents, except in DE where all inbreds in hybrid combination had the same rating. In the yield and GI rating, the present inbred ZS1022 scored better than each of its parents.

Table 5 shows the yield response of the inbred ZS1022 in hybrid combination when compared to the other inbreds in hybrid combination which are planted at the same locations.

                  TABLE 5                                                          ______________________________________                                         YIELD RESPONSE                                                                 HYBRIDS      YIELD                                                             ______________________________________                                         ZS1022/tester inbred                                                                        78    105     131  158    184  211                                Environment  75    100     125  150    175  200                                ______________________________________                                    

ZS1022 shows higher yield response across all types of yield environments. ZS1022's yield response when compared with the environment increases from the low yielding environments to the high yielding environments. In low yielding environments, ZS1022 yielded 3.5 bushels better than the environment; in contrast, in high yielding environments, ZS1022 yields 9-11 bushels better than the environment.

                  TABLE 6A                                                         ______________________________________                                         HYBRID SUMMARY                                                                 HYBRID ZS1022                                                                  PERFORMANCE DATA-EXCLUDES WEST LOCATIONS                                       HY-                                    %   %    %                              BRID       N     GI     YM   YLD  MST  SL  RL   % DE                           ______________________________________                                         RE   8513      20    3.3  -0.3  4.6 -1.9 1.1 -0.1 0.0                          RE   8382      45    1.3  -0.4 -0.3 -1.3 1.1  0.5 0.0                          RE   8344      52    4.9   0.5  8.7  0.7 0.1  0.3 0.0                          RE   8321      20    1.2   0.0 -1.9  0.5 1.0  1.2 0.0                          ______________________________________                                    

The hybrid containing ZS1022 appears to do better in the east than the west due to apparent lack of adaptation in the other inbred to western environments. Hybrid 8513 is compared with a hybrid containing ZS1022. Positive ratings indicate hybrid ZS1022 has the advantage, negative ratings indicate the non ZS1022 hybrid has the advantage. ZS1022 has the advantage in G index, yield, resistance to stalk lodging and dropped ears. In the comparison with 8382, the ZS1022 hybrid again shows a G index advantage and a resistance to stalk and root lodging and dropped ear advantage. In the comparison with 8344, ZS1022 has across the board advantages from yield to moisture to resistance to stalk and root lodging. ZS1022 shows excellent advantage over 8321 in all categories except in yield.

                  TABLE 6B                                                         ______________________________________                                         AGRONOMIC DATA                                                                 HYBRID    N          ESTAND    VIGOR                                           ______________________________________                                         8513      5          7.3       1.1                                             8382      8          2.6       .8                                              8344      8          -1.0      1.2                                             8321      5          12.0      1.6                                             ______________________________________                                    

The information in Table 6B shows comparison of the four listed hybrids to the ZS1022 hybrid shown in Table 5. The data reflects the advantage the ZS1022 hybrid has over the listed hybrid. For example, ZS1022 in this hybrid combination has 7.3 more plants in early plant stand count than will 8513. The present inbred in hybrid combination has better early plant stand count than all the comparable hybrids except 8344. The vigor of ZS1022 in hybrid combination is superior to all of the listed hybrids. The good to excellent emergence of the inbred and the early vigor of the inbred in hybrid combination make this inbred in hybrid combination a choice for no tillage environments.

The foregoing is set forth by way of example and is not intended to limit the scope of the invention.

This invention also is directed to methods for producing a corn plant by crossing a first parent corn plant with a second parent corn plant wherein the first or second parent corn plant is an inbred corn plant from the line ZS1022. Further, both first and second parent corn plants can come from the inbred corn line ZS1022. A variety of breeding methods can be selected depending on the mode of reproduction, the trait, the condition of the germplasm. Thus, any such methods using the inbred corn line ZS1022 are part of this invention: selfing, backcrosses, hybrid production, crosses to populations, and the like.

Various culturing techniques known to those skilled in the art, such as haploid, transformation, and a host of other conventional and unconventional methods are within the scope of the invention. All plants and plant cells produced using inbred corn line ZS1022 are within the scope of this invention. The invention encompasses the inbred corn line used in crosses with other, different, corn inbreds to produce (F1) corn hybrid seeds and plants with the characteristics that make good hybrids. This invention includes cells which upon growth and differentiation produce corn plants having the physiological and morphological characteristics of the inbred line ZS1022.

Duncan, from at least 1985-1988 produced literature on plant regeneration from callus. Both inbred and hybrid callus have resulted in regenerated plants at excellent efficiency rates. Somatic embryogenesis has been performed on various maize tissue such as glume which before the 1980's was considered unuseable for this purpose. The prior art clearly teaches the regeneration of plants from various maize tissues. Stauffer Chemical, the predecessor to Zeneca Ag Chem, in European Patent Application, publication 160,390, incorporated herein by reference describes tissue culture of corn. Corn tissue culture procedures are also described in the literature as early as 1982.

A deposit of at least 2500 seeds of the inbred seed of of this invention is maintained by ICI Seeds, 2369 330th Street, Slater, Iowa 50244. Access to this deposit will be available during the pendency of this application to the Commissioner of Patents and Trademarks and persons determined by the Commissioner to be entitled thereto upon request. All restrictions on availability to the public of such material are removed upon issuance of the patent. The Applicant made a deposit of at least 2500 seeds of Inbred Corn Line ZS1022 with the American Type Culture Collection (ATCC), located at 12301 Parklawn Drive, Rockville, Md. 20852. The ATCC Accession No. is 97628. The seeds were deposited with the ATCC on Jun. 26, 1996 and were taken from the inbred seed deposit maintained by ICI Seeds. The ATCC deposit will be maintained in that depository, which is a public depository, for a period of 30 years, or 5 years after the last request, or for the effective life of the patent, whichever is longer, and will be replaced if it becomes nonviable during that period. Additionally, Applicant has satisfied all the requirements of 37 C.F.R. §§1.801-1.809, including providing an indication of the viability of the sample.

Inbreds designated LH are available from Holden's Foundation Seed, Inc. in Iowa. Inbreds designated MBS are available from Mike Brayton Seed in Iowa. Inbreds designated SGI are available from Seed Genetics, Inc. in New Jersey. Information on the ZS designations may be available from the PVP office.

Accordingly, the present invention has been described with some degree of particularity directed to the preferred embodiment of the present invention. It should be appreciated, though, that the present invention is defined by the following claims contrued in light of the prior art so that modifications or changes may be made to the preferred embodiment of the present invention without departing from the inventive concepts contained herein. 

We claim:
 1. Inbred corn seed designated ZS1022 seed of which has been deposited with ATCC and carry ATCC number
 97628. 2. A corn plant produced by the seed of claim
 1. 3. A tissue culture of regenerable cells of ZS1022 wherein the tissue regenerates plants having all the physiological and morphological characteristics of ZS1022 seed of which has been deposited with ATCC and carry ATCC number
 97628. 4. A tissue culture according to claim 3, the tissue culture selected from the group consisting of leaves, pollen, embryos, roots, root tips, anthers, silk, flowers, kernels, ears, cobs, husks and stalks, and cells and protoplasts thereof.
 5. A corn plant having all the physiological and morphological characteristics of ZS1022 regenerated from the tissue culture of claim
 3. 6. Hybrid seed produced by:(a) planting, in pollinating proximity, seeds of corn inbred lines ZS1022 and another inbred line; (b) inducing the lack of pollen production by the plants of one of the inbred lines; (c) allowing natural cross pollinating to occur between said inbred lines; and (d) harvesting seeds produced on plants of the inbred line of step (d).
 7. Hybrid seed produced by hybrid combination of plants of inbred corn seed designated ZS1022 of claim 1 and plants of another inbred line.
 8. Hybrid plants grown from seed of claim
 7. 9. A first generation (F1) hybrid corn plant produced by the process of:(a) planting, seeds of corn inbred lines ZS1022 seed of which has been deposited in the ATCC under deposit number 97628; (b) providing a pollen source; (c) inducing the lack of pollen production by the plants of one of inbred lines adapted to produce the hybrid seed from which hybrid seed will be harvested; (d) allowing pollination to occur on said inbred line adapted to produce hybrid seed; (e) harvesting seeds produced on plants of the inbred line of step (c); and (f) growing a harvested seed of step (e).
 10. A tissue culture of the regenerable cells of the corn plant of claim
 8. 11. A tissue culture of the regenerable cells of the corn plant of claim
 9. 